Crane



Dec. 27, 1927.

u. BAMBER'GER CRANE Filed March 4. 1926 Patented Dec. 27, 1927.

PATE-NT OFFICE.

UDO BAMBERGER, OI EIBERSWALDE, NEAR BERLIN, GERMANY.

GR N E.

Application fi led March 4, 1926, Serial No. 92,?51, and in Germany March 7, 1925.

The invention relates to cranes of the kind having compensating mechanism for main.

quired for raising and lowering the jib is kept down to a minimum, said mechanism including a sheave over which the load rope passes and which though movable is always situated to the rear of the jib pivot through the whole amplitude of movement of the jib. In cranes of this kind it has been proposed to mount the compensating sheave on the end of a lever pivoted to a rigid triangulated framework fixed to the crane chassis, said lever being connected by means of a rod or cable to the jib so that on the lufling of the jib the lever is rocked, thus moving the sheave to compensate for the shortening or lengthening of the load rope, with the upward or downward movement of the jib.

The object of the present invention is to provide a more simple construction of the compensating mechanism notably b the avoidance of such parts as a fixed triangulated support with a pivoted lever, and rods or cables for rocking the same, but which is nevertheless quite efiicientin operation.

Referring to the accompanyin drawings:

Figure 1 is a constructional orm of the crane given by way of example.

Figure 2, is a diagram of a working operation in three positions.

The jib a is adapted to rotate round a pivot o. The cable coming from the head 6 of the jibruns over a sheave c and over a fixed roller d to the drum e. The sheave 0 is supported by means of two struts f and g, the strut 9 being mounted by means of a pivot 72. to the top for instance of a travelling cabin. The strut is connected by means of a pivot 73 with the tail of the jib. The'roller 0 runs upon an axis which simul taneously represents an articulated connec- The lower edge of the jib and of the tion between the guide members 7 and member 9 are provided with'counter-welghts k and is.

On pulling in the jib the head of the jib guide passes from the position b (Figure 2) to the position b and thence to the position 6 At the same time the sheave 0 moves from the position 0 shown in full lines to the position 0 and thence to the. position 0 Owing to this movement the length of the cable between the rollers d, cand b is shortened and consequently with the wind: ing drum e, stationary the cable runs over the roller 6 in a downward direction, whereby the load is maintained in a horizontal plane as clearly indicated in Figure 1. The special rope guide affords the further advantage that the force acting upon the strut f and resulting. from the stresses upon the cable gives rise to a torque or turning move- What I claim and desire to secure by Letters Patent of the United States is a-compensating mechanism comprising two relatively movable struts pivoted toget 181 at one of their two extremities and a sheave mounted on said struts at their point of juncture, the other extremity of the first said struts being pivoted to the jib and movable with the lufling thereof, while the other extremity of the second of said struts is pivoted to a fixed point.

2. A lufiing crane of the kind set forth, comprising a jib pivoted between. its head and tail to the crane structure, means for lufiing said jib, a counter-weight on said tail,

1. In a lufling crane of the kind set forth,

a strut pivoted at one extremity to said tail and movable therewith, a second strut piv oted at one extremity to the other extremity of said first mentioned strut and its other extremity to a fixed point, said struts being thus relatively movable, a loadrope sheave mounted'at the point of juncture of the two struts, and a counterweight on said second mentioned strutl UDO BAMBERGER. 

